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Old March 23rd 07, 05:33 PM posted to rec.radio.amateur.antenna
Keith Dysart Keith Dysart is offline
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First recorded activity by RadioBanter: Mar 2007
Posts: 124
Default Revisiting the Power Explanation

On Mar 23, 11:05 am, Dan Bloomquist wrote:
Your example assumes that the reflected power will see the 50 ohms of
the generator. And I had shown you a condition where it will see a short
no mater what the 'output' impedance of the generator.


Truly, we have found the root of the disconnect.

Kindly compute the reflection coefficient at the connection where
a 50 Ohm line is driving a 75 Ohm line.

For your convenience, recall that RC = (Z2-Z1)/(Z2+Z1).

Now redo the same, except that the 75 Ohm line is one-half wavelength
long terminated in a short.

If you get the same answer, then you will see why the reflected
voltage in the example does not encounter a discontinuity at the
entrance to the generator and is therefore not re-reflected.

If you get a different answer, then some study of reflection
coefficient
is in order.

....Keith